I'm currently evaulating the the IAR tools that came with ATMEL's AT91SAM7S-EK eval kit(which uses the AT91SAM7S64). The IAR tools (using a Segger J-Link tool) don't appear to be able to debug ISR's very well, if at all. Before I go through all the hoops to get several $1000 to spend on evaulating the JTAG debugger enabled version of the KEIL tools, I was wondering if anyone out there who's using them would mind commenting on how well they work when debugging ISR's.